Geology topics
Source-linked reports with geographic coverage including San Francisco Bay.
Observed gravity values, station locations, terrain corrections, and Bouguer gravity data are provided as computer printout tabulations for the San Francisco Bay area, California.
No abstract available.
Radiocarbon dating is an important interdisciplinary tool for studies involving events and processes during the last 40,000 years of earth history, including studies involving marine transgressions and regressions, land subsidence, climatic changes, sedimentation rates and patterns, fault movements, and archaeology, among others. The potential value of a radiocarbon date is diminished, however, if adequate site data are not taken with the sample and do not accompany the date in publication. At a minimum, published dates should include an accurate location for the dated sample, type of material dated and method of dating, nature of the site, depth below surface (or other accurately defined datum) of date sample, stratigraphy of material overlying date sample, and the significance of the data in the study.
No abstract available.
The purpose of this release is to describe the approximate volumes and significant pollutional loading attributable to municipal and industrial wastewater discharged into the San Francisco Bay. The six receiving-water regions (fig.1) are the same as those used previously by Pearson, Storrs, and Selleck (1969) in describing results of the comprehensive wastewater-monitoring program conducted by the University of California, Berkeley, during the period 1960-64.
The "Program Design" for the San Francisco Bay Region Environment and Resources Planning Study represents a refinement, elaboration, and extension of the plans which formed the basis for the cooperative program between the Department of the Interior, Geological Survey, and the Department of Housing and Urban Development, Office of Research and Technology, formally recognized in the Letter of Agreement of October 24, 1969, and begun January 1, 1970. From the first, the study was recognized as an experimental pilot study, and new developments in the state-of-the-art in the earth sciences and in urban and regional planning were recognized as necessary. Indeed, the development of a suitable structure for such a program was considered one of the important parts of the experiment. Consequently, one of the stated goals of the Letter of Agreement was to produce a Program Design.
No abstract available.
This report presents basic criteria, in the form of tables and graphs, for each of the four methods of hydrologic design most commonly used in the San Francisco Bay region--flood-frequency analysis, Rational Method, unit-hydrograph method, and runoff simulation by means of hydrologic basin modeling. The term "hydrologic design" as used in this report refers to the computation of either design values of peak discharge or design hydrographs of storm runoff. The hydraulics of open-channel and pipeline flow and the actual design of appurtenances for conveying the runoff are not discussed in this paper. Use of the suggested criteria results in fairly close agreement between peak discharges computed by the flood-frequency and unit-hydrograph methods. Those peak discharges are not directly comparable with discharges computed by the Rational Method, in part because the results obtained by the Rational Method are affected by the values assigned to parameters for overland and channel flow. Those parameters are additional to the ones used in the flood-frequency and unit-hydrograph methods. A demonstration of runoff simulation by use of a hydrologic basin model is beyond the scope of this paper--such demonstrations are found in the appropriate references cited. However, this report does present an original technique for transposing storm rainfall in the region, storm transposition being commonly required to obtain the precipitation input used with hydrologic basin models.
A summary of water-temperature records is presented for data collected through September 1968 in the San Francisco Bay Subregion of California. This report is one of a series covering the 11 hydrologic subregions of the State and includes data for 87 stream sites. Water temperatures, in degrees Celsius, are summarized by months, years, and for the period of record. A description is included to identify each station where data were collected. A tolerance interval analysis indicated that 99 percent of the point water-temperature observations, determined either with thermograph probes or hand-held thermometers, should be ±0.6°C of the mean water temperature at the 95-percent confidence level. The probable total error ranges from ±0.8°C for periodic data to ±1.4°C for thermograph data.
Measurements of ground motion generated by nuclear explosions in Nevada were made for 37 locations near San Francisco Bay, California. The results were compared with the San Francisco 1906 earthquake intensities and the strong-motion recordings of the San Francisco earthquake of March 22, 1957. The recordings show marked amplitude variations which are related consistently to the geologic setting of the recording site. For sites underlain by a layer of younger bay mud or artificial fill, maximum horizontal ground velocities generally increased with thickness of the layer and were as much as ten times greater than those recorded on nearby bedrock. The maximum vertical velocities for these sites were between 1 and 3.5 times greater. Spectral amplification curves clearly define a “dominant ground period” of about 1 second for sites underlain by younger bay mud. For sites underlain by older, more consolidated sediments, no clearly defined “dominant ground period” was found. Maximum ground velocities for the older bay sediment sites were about twice those recorded on bedrock.
An experimental Fraunhofer line discriminator detected solar-stimulated yellow fluorescence (5890 A) emitted by Rhodamine WT dye in aqueous solutions. Concentration of 1 part per billion was detected in tap water 1/2-meter deep. In extremely turbid San Francisco Bay, dye was monitored in concentrations of less than 5 parts per billion from helicopter and ship. Applications include studies of current dynamics and dispersion. Potential applications of the technique could include sensing oil spills, fish oils, lignin sulfonates, other fluorescent pollutants, and chlorophyll fluorescence.